The technology disclosed relates to improved acousto-optic deflectors (AODs). In particular, it relates to compensation for subtle effects not previously addressed by AOD designers. A shifting center of gravity is described and addressed using advanced power equalisation strategies. Denser writing brushes are provided by using a two-dimensional array of beams with corrections for factors such as angle of incidence at the AOD interface.
An acousto-optic deflector is driven by an induced ultrasonic acoustic wave through a crystal, such as a TeO2 crystal. Typically, this wave is a so-called chirp or sawtooth wave. The chirp has a bandwidth, which is the difference between the minimum and maximum frequency. The maximum range of deflection from the AOD corresponds to this bandwidth. The scan frequency corresponds to the period of the chirp. The shorter the chirp, the more frequently the deflector scans a beam through its range of deflection.